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genopower · 07-26-2021, 11:55 AM

I have a 2003 Safari Sahara with a ISC 8.3 Cummins turbo diesel. There's a fuel filter and seperator. When I go to change them diesel fuel just keeps pouring out. Is there a way to shut off the flow before I change them? I included a pic of my set up. Thanks.

Caymanedge · 07-26-2021, 12:19 PM

There is a vacuum from the tank that keeps the fuel flowing. You can look for a shut-off or try and crimp the line. The separator just needs drained so that's easy. The filter requires a change. My Cummins has a primer process to get fuel back into the filter and line. However, I found if I fill the new filter with fuel and swap them quickly it will start almost right up.

153stars · 07-27-2021, 06:17 AM

The lines are like hydraulic I wouldn't try crimping shut.. Try opening fuel cap to make sure no pressure in tank. Try to find small tub to fit under. I would rather deal with the fuel than have nothing but air all through fuel lines.

jacwjames · 07-27-2021, 07:11 AM

My rig does not have any type of shutoff so in the past I would use a drain pan under the filter to capture as much as possible. You might consider adding a valve on the feed side of the primary filter when you do your first filter change, just have to make sure you turn it back on.

I believe the filter on the left is you primary filter, which you should change first. In the past I didn't prefill the filters but ~6 years ago I had a heck of time getting the rig started by cycling the key on/off 4-5 times. Since then I just prefill the filter with clean diesel & plugging the center hole.

I have since installed a FASS system which primes everything fully so I shouldn't have to prefill.

Good luck.

Lowflyer1 · 07-27-2021, 07:18 AM

It might also help to change the filters with lower fuel level depending on where the filters are in relation to tank level.
Mine is the opposite, when I open the sediment valves at the bottom of the filters, hardly nothing comes out.

okcnewbie · 07-27-2021, 07:35 AM

Quote:

Originally Posted by Caymanedge

....The separator just needs drained so that's easy. .

This sounds wrong to me. My manual says the Primary filter (water/fuel seperator) needs changed every 6 months or 15k miles. More often if you have power loss. One tank of bad fuel can clog the filter. Just draining the water will still not unclog it.

ArtJoyce · 07-27-2021, 07:38 AM

For me its gravity feed from the tank. If you look at your tank in relationship to your frame and you look at your filters in relationship to the frame. I think you will fing the filters are lower then the top of the tank?

When I go to change my filters. I try to do it when the tank is about 1/2 full. My filters are near the rear axles. So I lift the rear end with my rear jacks making sure I dont lift the tires off the ground. Also chock your front tires. The parking brake is only applied to the brakes on the rear axles. At this point the filters are above the fuel in the tank and fuel does not flow out other than what in the filter..

wolfe10 · 07-27-2021, 07:47 AM

Quote:

Originally Posted by ArtJoyce

For me its gravity feed from the tank. If you look at your tank in relationship to your frame and you look at your filters in relationship to the frame. I think you will fing the filters are lower then the top of the tank?

When I go to change my filters. I try to do it when the tank is about 1/2 full. My filters are near the rear axles. So I lift the rear end with my rear jacks making sure I dont lift the tires off the ground. Also chock your front tires. The parking brake is only applied to the brakes on the rear axles. At this point the filters are above the fuel in the tank and fuel does not flow out other than what in the filter..

Correct.

If the level of the fuel in the tank is ABOVE that of the filter head, fuel will flow out the filter housing. If the filter head is above the level of fuel in the tank, fuel will flow back to the tank. This is even worse than leaking fuel, as it leaves you with 30+ feet of AIR in the fuel line to purge.

If you are not going to modify (next paragraph), then the answer is to have the new filter ready to go. If separate filter element base, buy an extra one, so the filter is ready to go.

The real solution is to install a diesel compatible BALL VALVE on the intake side of the primary filter. Turn it off before changing filters. It also makes a heck of an anti theft device.